Guix absolutely supports ZFS[1] without root or /home on it.
The user-space daemon for auto-mounts might take some setup, but there's a guide[2]*. I've personally gone all-in and use Guix with ZFS-on-Root, but this isn't an officially supported configuration due to an unfortunate cluster-truck[3] of an issue, and I haven't shared my configuration publicly yet (might soon for other reasons, but it's just not there yet).
The user-space daemon for auto-mounts might take some setup, but there's a guide[2]*. I've personally gone all-in and use Guix with ZFS-on-Root, but this isn't an officially supported configuration due to an unfortunate cluster-truck[3] of an issue, and I haven't shared my configuration publicly yet (might soon for other reasons, but it's just not there yet).
1: https://packages.guix.gnu.org/packages/zfs/
2: https://www.reddit.com/r/GUIX/comments/s7qu25/guide_using_zf...
3: https://issues.guix.gnu.org/45692
*: Accessing ZVOLS through `/dev/zvol/foo/bar` takes additional setup.